Changes in the heritable attributes of populations of organisms over time. The mechanisms of evolution are mutation, migration, drift, and selection.

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What's the difference between evolution fitness and reproductive success?

What's the difference biological fitness and reproductive success in the biological terminology?
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1answer
129 views

Why does evolution only involve heritable traits?

If natural selection favors a certain behavior that is learnt, then wouldn’t that behavior be found more often among a population (as more offspring will learn that behavior from their parents or ...
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515 views

Why haven't land animals evolved beyond urination?

It occurred to me (while urinating) that this would seem to be selected against because water is a scarce resource. Why are we constantly losing water we don't need to through urination? What is ...
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7answers
10k views

How do we know that humans and chimpanzees evolved from a common ape ancestor? [closed]

Richard Dawkins in one of his videos says that Evolution is a fact and not just a theory. He goes on to say that man and chimpanzees both evolve from apes. Is this correct (Is evolution a fact and ...
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1answer
216 views

Was Darwin aware of the difficulties behind the concept of species?

Introduction The concept of species is a very old concept that suffers from not being a natural category. There exists no single definition that would categorize living beings into groups and that ...
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260 views

Sequence evolution simulation tool

I'm looking for a tool to simulate sequence evolution given a specific mutation model and birth-death model. I'm aware of tools and packages like INDELible, Seq-Gen and PhyloSim, but they simulate ...
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1answer
54 views

Why is the probability of fixation of an allele equal to its frequency?

Introduction In a panmictic population, the probability of fixation of an allele at a neutral locus is equal to its frequency at that time. I will refer to this probability of fixation as calculated ...
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0answers
40 views

Is diarrhoea advantageous to the microbe?

Diarrhoea is a common side effect of many feco-orally transmitted bacterial infections. How does diarrhoea help the pathogen? Should it not have a selective evolutionary advantage? Do all symptoms of ...
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4answers
770 views

How did the first life form on Earth reproduce without DNA?

How did the earliest life forms exist without DNA? The most likely scenario I can think of for life happening from nothing is that, over billions of years, with trillions of water molecules and dust ...
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1answer
84 views

What is different between the pigment of giraffes and the pigment of flowers?

I saw this video created by Derek Muller and he says there that it is very unusual to evolutionary develop the colour of the skin without the pigment. That sounds reasonable but if so, what nutrients ...
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185 views

Approaches towards a theory of innovation in evolution

Evolutionary biologist Andreas Wagner writes in his book "The Origins of Evolutionary Innovations: A Theory of Transformative Change in Living Systems" (Oxford University Press, 2011): We are ...
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2answers
72 views

Infer gene frequency within a species over time

I was reading Karlsson et al. (2014) and I came into this: A selected variant that increases rapidly in frequency in the past ~250,000 years can be detected as an unusual reduction in genetic ...
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3answers
141 views

Intuitive explanation for Kin- and Group- selection

It is known from theoretician in the field of kin selection that kin selection (inclusive fitness theory) and group selection are actually two sides of the same coin. In other words, these two ...
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94 views

Did toads evolve from frogs?

I know frogs still exist but that doesn't mean there wasn't ever a frog population that evolved into toads. Did frogs evolve into toads because their available swamp slowly went away and toads could ...
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1answer
24 views

Measuring tumor heterogeneity [closed]

I would like to ask if there's any method (established or not) in order to quantify heterogeneity found in mutations occuring in primary neoplasms and metastatic lesions (either common or private) and ...
3
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0answers
51 views

Is $F_{ST}$ a probability and a correlation coefficient?

$F_{ST}$ is one of the most famous and most important statistics of all of evolutionary biology. Yet, many people misunderstand it or misuse the classical results from the literature on $F_{ST}$ (...
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1answer
44 views

How to compare diversity between different ecosystems?

I've used the Shannon Wiener Diversity Index for a single ecosystem (species as categorical variables). Do you know any alternative indices, especially ones that compare diversity between different ...
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1answer
62 views

First life forms to evolve controlled flight

What was the first living organism able to fly in the skies and control their direction , not just Aeroplankton like bacteria and viruses carried by the winds but something like an winged insect or ...
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1answer
149 views

Why does Citric Acid occur in Citrus fruits?

Why is there so much citric acid in citrus fruits? And how did it evolve i.e. what did it come from? Is it a by-product of the ripening process? Why have citrus fruit evolved a particularly high ...
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123 views

Effect of sex-ratio on the effective population size

As stated on this wikipedia article, the effective population size $N_e$ when the sex ratio differs from $\frac{1}{2}$ is $$N_e = \frac{4N_mN_f}{N_m+N_f}$$ I understand the biased sex-ratio ...
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3answers
228 views

How scientists can be confident that human embryo tail is really a tail?

From Wikipedia: Human embryos have a tail that measures about one-sixth of the size of the embryo itself. As the embryo develops into a fetus, the tail is absorbed by the growing body. How are ...
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2answers
514 views

What modern insects are not (flying OR descended from flying ancestors)?

What modern insects are not flying or descended from flying ancestors? (I read somewhere that 99% are, so of course I instantly became curious which aren't. xD ) EDIT: Sorry, I should have been ...
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2answers
2k views

Why did the urinary bladder evolve?

Sure it's convenient to decide when to urinate but not essential for survival or reproduction, as I understand. But just convenience is not a drive for evolution. Does the bladder serve any essential ...
2
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0answers
47 views

Why were dinosaur skeletons so light compared to mammal skeletons?

I was watching a presentation by Dr. Jessica Theodor [1] who discusses (at 38:10), among other things, the skeletal structure of dinosaurs vs. mammals. "Dinosaurs have way lighter skeletons, which ...
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How were (many) dinosaurs' brains so small?

Brain size (or its proxy, encephalization quotient) usually varies allometrically with mass -- larger creatures need larger brains to control their larger bodies, apparently. Dinosaurs are popularly ...
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1k views

If oxygen is such a good energy source, why do plants release it?

Why do plants release excess oxygen, rather than consuming it entirely given it is an excellent energy source?
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4answers
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Why would a plant evolve to produce an addictive chemical?

It seems kind of anti-productive in terms of survival for a plant to produce an addictive chemical as that plant will constantly be sought after by animals that ingest it. In this instance, I'm ...
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58 views

Current scientific theories for evolution of Cucurbita

I'm attempting to find research on scientific theories surrounding the evolution of certain plants, and am unable to find any footing with respect to a certain genus. In this case, I am researching ...
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79 views

Does cancer cells come from same process as evolution? [duplicate]

Here is how I understand it: DNA replication is not 100% perfect and error can happen, this error can be good(evolution) or bad(cancer properties). But its not the only source of cancer cells - DNA ...
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1answer
37 views

the evolution of the human brain size [closed]

I was thinking, as I know, sometimes the process of producing DNA did not work well(correct me if I'm wrong), so it gives us some changes in the object we gonna ...
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2answers
120 views

Are humans evolving since their first appearance? [duplicate]

Is the evolution a very prolonged progress, or are we going to witness further evolution of the human species? If so, in which direction? Are there any widely predicted changes for humans?
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547 views

Genetic Diversity and Adaptation

I am somewhat new to evolutionary biology, having studied it on my free time as a computer science student. There is one particular thing that has always bothered me for which I have not seen a good ...
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128 views

Why do fetuses have membranes between fingers and toes?

Are the membranes present between the fetal fingers and toes a remainder of the phylogenetic evolution, or just a way organs do grow most easily?
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2answers
966 views

Viral Mutation Mechanism

I think I have a wrong concept about viral mutation process. First of all what is mutation actually? I mean, I know it's a sudden change in DNA, happening when subjected to mutagenic agents. But can ...
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5answers
492 views

Is it the case that all changes in phenotype during life are not inheritable?

This came up in a talk with a friend. I wanted to clear this doubt. I've read about it before and did again after her remark (my thoughts didn't change: her concept is Lamarck's, not Darwin's), but ...
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85 views

How do minute changes in an organism, as a result of evolution, get carried over to next generation

The theory of evolution states that random variations in organisms occur to better suit their surroundings. We take for example a bacteria's flagella. There's a bacteria who has a tube kind of ...
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77 views

What were the Neanderthal innovations?

At some point the neanderthal and modern human lineages diverged. I'm not sure what exactly their most common recent ancestor was (I see some sources suggesting homo heidelbergensis), but in any case ...
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2answers
197 views

How to define “evolution”?

The standard answer to the question: what is evolution? is: It is a change in allele frequency over time! I believe a complete definition should encompass the following concepts: ...
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193 views

What traits make mountain goats so well adapted to mountain living?

I've never really understood how mountain goats manage to survive so well in mountainous regions. I've seen them scale almost sheer cliff faces with apparent ease, and they can almost sprint ...
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150 views

Can we say the 'goal' of Mullerian mimicry is a 'decrease in the number of sacrificed indivials'?

Can we say that Mullerian mimicry allows two species to decrease their number of sacrifice individuals because: Originally, one species needs to sacrifice some individuals to allow predators to ...
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1answer
41 views

Is there any evidence that any other species are “pre-intelligence”? [closed]

Is there any evidence regarding whether other species might, given time, evolve intelligence as humans have? I realize "intelligence" is a vague word here, but I'm interested in throwing a wide net, ...
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1answer
39 views

Does the species of snake that eats Amphidromous inversus have chiral dimorphism?

From what I read at Schilthuizen and Davison (2005), Amphidromous inversus is a species of snail that occurs in 2 forms that are nearly mirror images of each other occurring in nearly equal ...
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6answers
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Why are there no organisms with metal body parts, like weapons, bones, and armour? (Or are there?)

Reading this question, Why are there no wheeled animals?, I wondered why no organisms seem to make use of the tensile and other strengths of metal, as we do in metal tools and constructions. I am ...
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42 views

Origin of aerobic respiration [closed]

Since life originated in water, did the first eukaryotic organisms utilize the dissolved oxygen in the water or they respired anaerobically?
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0answers
25 views

Describing trait evolution across a very small phylogenetic tree [closed]

I am very new to phylogenetic comparative methods but I want to explore the evolutionary patterns of a number of quantitative traits I have across a small sample (5) of closely related species (...
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5answers
5k views

Why do living fossils like crocodiles remain so constant and not evolve? [duplicate]

Crocodiles have supposedly remained unchanged for millions of years, and several other species are considered as "living fossils". How do such species remain so constant over time given that they will ...
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How much of the genetic differences between humans and chimpanzees are due to genetic drift?

Both natural selection and genetic drift play a part in changing our DNA over time. Are there trustworthy estimates how much of the differences over the whole genome between us and chimpanzees are due ...
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2answers
96 views

How to name a case of convergent evolution where the same mutation is involved in both lineages?

Definition of Convergent evolution - from Wikipedia > Convergent Evolution Convergent evolution is the independent evolution of similar features in species of different lineages. Convergent ...
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1answer
54 views

How do I measure genetic distance?

I'm not sure how to measure genetic distance. There seems to be many different equations out there, and all the ones I found are rather old. In my specific problem I want to see if the twist in ...
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1answer
66 views

Development and function of spindle neurons

In his book How to Create a Mind author Ray Kurzweil makes some claims about spindle neurons that he provides no source for. Concretely he states that spindle cells: Are Involved in handling ...